JP2006346601A - Filtration apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filtration apparatus realizing miniaturization of the apparatus and enhancing a water removal performance. <P>SOLUTION: The filtration apparatus is provided with a concentrically arranged cylindrical or conical inner filter medium 1; an outer filter medium 2; and a spiral partition 3 provided in a filtration space 11 between the inner filter medium 1 and the outer filter medium 2. A storage space for storing a liquid to be treated is formed between one end side of a casing 7 fed with the liquid to be treated and an end plate 1B of the inner filter medium 1 and a filtration space is formed between an outer peripheral surface of the inner filter medium 1 and an inner peripheral surface of the outer filter medium 2 so as to be communicated with the storage space. The inner filter medium 1 and/or the outer filter medium 2 are rotated around an axis and the spiral partition 3 is not rotated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a filtration device.

Filter materials such as metal screens, nets, perforated plates, etc. are superior in terms of operability, maintainability, durability, etc. compared to cloth (fiber) products. There is a pressure filtration device such as a rotary pressure dehydrator. Since this device has a long history and has a very simple structure, it is characterized by low power, low noise, low cost, and even when applied to a hard-to-dehydrate solid-liquid mixture with a low solid content. Because of its excellent dewatering performance, it is often used in the sewage sludge dewatering field. (For example, see Patent Documents 1 and 2)
JP 2001-212697 A JP 2001-113109 A

  However, in a screw press comprising a cylindrical outer filter medium and a screw inserted therein, the liquid to be treated is transferred from the inlet side to the outlet side at a low speed, and at the same time, generated by the tightening force of the screw. Although it is continuously dehydrated by the pressing pressure, since the filtrate is squeezed out only from the outer filter medium, it is difficult to shorten the length of the outer filter medium, and it is difficult to downsize the equipment.

  On the other hand, in the rotary pressurization type dehydrator, it is necessary to increase the diameter of the disk or to arrange a plurality of dehydrators in order to improve the throughput of dehydration filtration. It was.

  Then, the main subject of this invention is providing the filtration apparatus which aims at size reduction of an apparatus and improves dehydration performance.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
The invention according to claim 1 is provided between a cylindrical or conical inner filter medium and an outer filter medium disposed concentrically in the casing, and an outer peripheral surface of the inner filter medium and an inner peripheral surface of the outer filter medium. A spiral partition, which feeds the liquid to be treated from one end side of the casing, discharges the cake from the other end side of the casing, and passes through the inner filter medium and the outer filter medium. A storage device for storing the liquid to be treated is formed between the one end side of the casing and the end plate of the inner filter medium, and communicated with the storage space. A filtration space is formed between the outer peripheral surface of the inner filter medium and the inner peripheral surface of the outer filter medium, the inner filter medium and / or the outer filter medium rotate around an axis, and the spiral partition does not rotate Filtration characterized by A filtration device comprising a to place.

(Function and effect)
By performing filtration and concentration with two surfaces of the inner filter medium and the outer filter medium, it is possible to reduce the size of the equipment as compared with a screw press that performs filtration only with a conventional outer filter medium. In addition, the inner filter medium and / or the outer filter medium rotate around the axis and the spiral partition does not rotate, so that the liquid to be treated fed into the filtration space is spirally installed along the partition. While moving inside, first, filtration and concentration by the two sides of the inner and outer filter media is performed, and then press dewatering is performed, but not only the inner and outer filter media but also the ribbon screw, all of which are configured to be freely rotatable compared to the screw press The filtration device according to the present invention can simplify the structure, reduce the manufacturing cost, and improve the maintainability. Furthermore, by forming a storage space for storing the liquid to be processed between one end side of the casing into which the liquid to be processed is fed and the end plate of the inner filter medium, a certain amount of processing can be secured. , Processing efficiency can be improved.

<Invention of Claim 2>
According to a second aspect of the present invention, in the storage space, a blade plate that rotates about the coaxial center with the inner filter medium and the outer filter medium is provided. The filtration device according to claim 1, wherein the filtration device is configured to pump in a radial direction.

(Function and effect)
By agitating the liquid to be treated with the blades and pumping the liquid to be treated in the radial direction, the filtration efficiency can be improved and the movement of the liquid to be treated in the filtration space can be promoted.

<Invention of Claim 3>
The invention according to claim 2 is that the end plate of the inner filter medium is formed of a filter medium so that the storage space is the first filtration space, and the outer peripheral surface of the inner filter medium and the inner peripheral surface of the outer filter medium It is the filtration apparatus of Claim 1 or 2 which comprised the filtration space between as 2nd filtration space.

(Function and effect)
Since the end plate of the inner filter medium is formed of the filter medium, the storage space can be made the first filtration space, so that the filtration efficiency is higher than that of a conventional filtration device using only the side surface of the screen as the filtration surface. Can be improved.

<Invention of Claim 4>
The invention according to claim 2 is configured such that the blade plate is close to or in contact with the filtration surface of the end plate of the inner filter medium, and the blade plate and the inner filter medium rotate with a speed difference. This is a filtration device.

(Function and effect)
By making the blade plate close to or in contact with the filtration surface of the end plate of the inner filter medium, and making the blade plate and the inner filter medium rotate with a speed difference, the cake stuck to the filter surface is scraped off and concentrated by filtration. Efficiency can be maintained.

<Invention of Claim 5>
According to a fifth aspect of the present invention, at least the inner peripheral edge and the outer peripheral edge of the spiral partition on the inlet side of the liquid to be processed are close to or in contact with the inner filter medium and the outer filter medium, respectively. It is a filtration device given in any 1 paragraph.

(Function and effect)
Since the liquid to be treated sent into the filtration space has a low cake concentration and fluidity, filtration and concentration are caused by the inner and outer filter media near the inlet of the liquid to be treated. Therefore, filtration concentration by solid-liquid separation is an important function near the inlet side of the liquid to be processed, but at least the inlet side of the liquid to be processed (the lower part of the second filtration space) of the spiral partition. By making the inner peripheral edge and the outer peripheral edge close to or in contact with the inner filter medium and the outer filter medium, respectively, the cake adhered to the filtration surface of the screen is scraped off, and the efficiency of filtration concentration can be maintained. In addition, the fed liquid to be processed can be spirally moved along the partition.

<Invention of Claim 6>
The invention according to claim 6 is the filtration device according to any one of claims 1 to 5, wherein the rotation speed of the inner filter medium and the rotation speed of the outer filter medium are rotatable with a speed difference.

(Function and effect)
When the rotation speed of the inner filter medium and the rotation speed of the outer filter medium rotate with a speed difference, a shearing force is generated in the cake moving in the filtration space (second filtration space). Therefore, for example, for a liquid to be treated containing raw sludge having a high fiber content or mixed raw sludge, the dewatering efficiency can be improved by this shearing force. In addition, when the relative speed of each of the inner and outer filter media is large, the cake in the vicinity of the rapidly rotating filtration surface (for example, the filtration surface of the inner filter media) moves to the other filtration surface (for example, the filtration surface of the outer filter media). The effect appears and the mixing action in the cake occurs, so that the moisture content distribution in the filtration device can be made uniform.

<Invention of Claim 7>
According to a seventh aspect of the present invention, the inner filter medium is provided with a first rotation drive means, and the outer filter medium is provided with a second rotation drive means. The first rotation drive means and the second rotation drive means. The filtration device according to any one of claims 1 to 6, wherein the filtration device is a rotation driving means different from the means.

(Function and effect)
It is possible to improve the dewatering efficiency by applying shear force to the cake due to the difference in rotation speed between the inner and outer filter media, but this effect depends on the properties of the target cake. It is necessary to set the speed difference between the inside and outside. In the present invention, the difference in speed between the inside and outside can be easily adjusted in accordance with the cake properties by using a rotation driving means different from the first rotation driving means and the second rotation driving means.

<Invention of Claim 8>
The invention according to claim 8 is configured so that the pitch interval of the spiral partition is shortened from the one end side to the other end side. The filtration device according to item.

(Function and effect)
The spiral partition is configured so that the pitch interval becomes shorter as it goes from one end side to the other end side of the filtration space, thereby narrowing the discharge path of the cake and enhancing the squeezing effect, thereby discharging the cake It is possible to eliminate the unevenness (distribution) of the moisture content of the water and make it uniform.

<Invention of Claim 9>
The invention according to claim 9 is configured such that the axial center is vertically oriented, the entire apparatus is vertically oriented, and the liquid to be treated is fed in a pressurized state from below to above. The filtration device according to any one of 1 to 8.

(Function and effect)
Depending on the properties of the cake, the degree of progress of dehydration and the design of the filter chamber volume may not be balanced, and the cake filling rate may decrease. In this case, in the configuration in which the filtration device is arranged sideways (horizontal type), the filtrate is affected by gravity and leaches into a cake having a low filling rate, so that the moisture content of the discharged cake is increased. is there. Accordingly, the axial center is vertically oriented, the entire apparatus is vertically oriented, and the liquid to be treated is fed upward using gravity by being configured so that the liquid to be treated is fed in a pressurized state from below to above. It is possible to prevent the cake from being leached to the cake discharge side, and therefore, it is possible to eliminate unevenness (distribution) of the moisture content of the discharged cake and make it more uniform.

<Invention of Claim 10>
A tenth aspect of the present invention is the filtration device according to any one of the first to eighth aspects, wherein the axial center is laterally oriented and the entire device is laterally disposed.

According to the present invention, there are advantages that the apparatus can be downsized and the dewatering performance can be improved.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
<Configuration of filtration device according to the present invention>
As shown in FIG. 1 and FIG. 2, an inner cylinder rotating shaft to which a driving force is transmitted by a first rotation driving means (not shown) such as a motor is disposed inside the casing 7 in the filtration device according to the present invention. A rotatable cylindrical inner filter medium 1 having an upper plate 1A coupled to 5; a rotatable cylindrical outer filter medium 2 disposed concentrically with the inner filter medium 1; and an upper plate 7A of the casing 7 A spiral-shaped (ribbon screw-shaped) partition 3 having an end portion fixed and disposed in a space formed between the inner filter medium 1 and the outer filter medium 2 is provided. A storage space (first filtration space) 4 is formed between the bottom plate 1B which is an end plate of the inner filter medium 1 and the bottom plate 7B of the casing 7, and the inner filter medium 1 and the outer filter medium 2 described above Between, the 2nd filtration space 11 connected to the storage space (1st filtration space) 4 is formed. In addition, although the casing 7 is a cylindrical shape in this Embodiment, it is not restricted to this, Shapes, such as a polyhedron, may be sufficient.

  As shown in FIG. 1, a liquid feed pipe 10 to be treated is connected to the bottom plate 1 </ b> B of the inner filter medium 1. The tip of the liquid feed pipe 10 to be processed penetrates the bottom plate 7B of the casing 7 and is inserted into the casing 7, and supply ports 10A, 10A,. The liquid to be processed is fed into the casing 7 through the supply ports 10A, 10A,. Further, the liquid feed pipe 10 to be treated also functions as a support shaft that supports the rotation of the inner filter medium 1, and the liquid feed pipe 10 to be treated is rotatably held by a bearing attached to the bottom plate 7 </ b> B of the casing 7. Yes.

  The liquid to be treated is pumped by a pump (not shown), and along with this pressure, the pressure from the rotation of the vane plate 6 described later and the friction from the rotation of the inner filter medium 1 and the outer filter medium 2 cause the bottom to the top of the casing 7. It will rise. In the case where the axial center of the apparatus itself is set sideways and the entire apparatus is arranged sideways, the liquid to be treated is pumped by the rotation of the blade plate 6 and the rotation of the inner filter medium 1 and the outer filter medium 2 without pumping the liquid to be treated. The inside of the apparatus may be moved only by the frictional force.

  The space between the bottom plate 1B of the inner filter medium 1 and the bottom plate 7B of the casing 7 has a relatively large volume, and is supplied from supply ports 10A, 10A,... It functions as a space (storage space) for storing the liquid to be processed, and contributes to an improvement in processing efficiency. In addition, by configuring the bottom plate 1B of the inner filter medium 1 with a filter medium such as a wedge wire, which will be described later, this space can be a filtration space (first filtration space 4) that can be filtered and concentrated. Filtration efficiency can be improved as compared with a conventional filtration device using only the side of the screen as the filtration surface. Of the liquid to be treated, the filtrate that has undergone solid-liquid separation is discharged from a filtrate outlet 12 formed on the bottom surface 1B of the inner filter medium 1, as shown in FIGS.

  Further, blade plates (impellers) 6, 6,... Are attached to the liquid feed pipe 10 so as to be adjacent to the supply ports 10A, 10A,... As the inner filter medium 1 rotates. It is designed to rotate. The blades 6, 6,... Agitate the liquid to be treated supplied from the supply ports 10 </ b> A, 10 </ b> A,..., And pump the liquid to the outer filter medium 2 forming the outer peripheral portion. Has a function to raise. It should be noted that the liquid feed pipe 10 to be treated and the inner filter medium 1 are structurally separated so that they do not rotate together (for example, the inner filter medium 1 is rotated by another rotational driving means) and the blades. By attaching a scraper (not shown) to the upper edge of the plates 6, 6,..., The cake captured on the filtration surface can be scraped off with this scraper.

  On the side surface (outer peripheral surface) of the inner filter medium 1, a wedge wire is stretched as a filter medium, and the slits of the wedge wire are arranged along the rotation axis. Among the liquids to be treated that have passed through the first filtration space 4 and moved to the second filtration space 11 formed between the inner filter medium 1 and the outer filter medium 2, one of the filtrates subjected to solid-liquid separation. As shown in FIGS. 1 to 3, the portion is discharged from a filtrate outlet 12 formed on the bottom surface 1 </ b> B of the inner filter medium 1.

  The outer filter medium 2 has a structure in which the upper end of the outer periphery is suspended from the upper plate 7A of the casing 7 by a rail and a roller guided by the rail, and the side surface of the upper end is not shown. The outer filter medium 2 itself is connected to an outer cylinder rotating shaft (not shown) to which a driving force is transmitted by a second rotation driving means (not shown) such as a motor via a pinion gear (not shown). Is designed to rotate. Further, similarly to the inner filter medium 1, a wedge wire is stretched as a filter medium on the inner peripheral surface of the outer filter medium 2. The slits of the wedge wire are arranged along the rotation axis, and among the liquid to be treated sent into the second filtration space 11, a part of the filtrate that has been subjected to solid-liquid separation is part of the casing 7 and the outer filter medium. 2 is stored in the bottom plate 7B between the two and finally discharged from the filtrate outlet 13.

  Here, even when the inner filter medium 1 and the outer filter medium 2 are rotated at the same angular velocity (° / sec), the peripheral speed (mm / sec) of each radial difference is generated, so that shear force is generated in the cake. Thus, dewatering efficiency is improved. For example, for the liquid to be treated containing raw sludge having a high fiber content or mixed raw sludge, since this shear force is more effective, a slight speed difference is given to the inner filter medium 1 and the outer filter medium 2, By rotating it, it is possible to further improve the dehydration efficiency. Moreover, when the relative speed of the inner side filter medium 1 and the outer side filter medium 2 is large, the cake in the vicinity of the filtration surface (for example, the filtration surface of the inner filter medium 1) that rotates rapidly is the other filtration surface (for example, filtration of the outer filter medium 2). The effect of migrating to the surface) side appears, and the mixing action in the cake occurs, so that the moisture content distribution in the filtration device can be made uniform.

  As described above, the shearing force is applied to the cake due to the difference in angular velocity between the filtration surfaces of the inner and outer filter media 1 and 2, and the dewatering efficiency is improved. However, this effect depends on the properties of the target cake, so that it operates in an optimum state. In this case, it is desirable to set the speed difference between the inside and outside according to the cake properties. For this reason, in this embodiment, the inner and outer filter media 1, 2 are provided with rotational drive means such as individual motors so that the speed difference can be easily adjusted.

  On the other hand, depending on the cake properties, when a shearing force is applied, the cake may be fluidized, and conversely, the dewaterability may be impaired. In such a case, it is preferable to rotate the cake at a constant speed difference. In addition, for cakes that have a dehydration effect due to shearing force and the cake properties hardly change throughout the year, they may be rotated at a constant speed difference. May be rotated at the same speed by a single motor.

  The inner filter medium 1 and the outer filter medium 2 do not necessarily need to be rotated, and only one of them may be rotated.

  The filter medium used for the inner and outer filter media 1 and 2 is not limited to the wedge wire, and a punched plate (not shown), a wire mesh (not shown), a filter cloth (not shown), or the like can be used. . Moreover, since the bottom plate 1B of the inner filter medium 1 forming the first filtration space 4 and the lower part of the second filtration space 11 are mainly solid-liquid separation, these filtration surfaces are configured with wedge wires having a high aperture ratio. And you may arrange | position the punching board with a high contact area with a cake (low opening rate) in the upper part of the 2nd filtration space 11 by which compression dehydration is main.

  As shown in FIGS. 1 and 5, the partition 3 has a spiral shape (ribbon screw shape), and is disposed in an annular second filtration space 11 formed between the inner filter medium 1 and the outer filter medium 2. Has been. Since the partition 3 is fixed to the upper plate 7A of the casing 7, the partition 3 does not rotate around the axis. As a result, the filtration device according to the present invention can simplify the structure, reduce the manufacturing cost, and improve the maintainability, compared to a screw press that can rotate not only the inner and outer filter media but also the ribbon screw. Can be achieved.

  The inner peripheral edge and the outer peripheral edge of the partition 3 are configured to be close to or in contact with the filtration surfaces of the inner filter medium 1 and the outer filter medium 2, respectively. With this configuration, it is possible to easily scrape the cake adhered to the filtration surfaces of the inner and outer filter media 1 and 2, maintain the efficiency of filtration concentration, and spirally feed the liquid to be treated along the partition 3. Can be raised. Since the lower part of the second filtration space 11, that is, the vicinity of the supply ports 10A, 10A,... Is mainly subjected to filtration and concentration by solid-liquid separation, at least the inner peripheral edge and the outer peripheral edge of the partition 3 are to be processed. The liquid supply ports 10 </ b> A, 10 </ b> A,...

  Further, as shown in FIG. 5, by attaching a scraper 16 formed of rubber or the like to the inner and outer peripheral edges of the partition 3, the inner filter medium 1 and the outer filter medium 2 rotate around the axis, and the partition 3 rotates. Due to the non-configuration, the cake captured on the filtration surface can be scraped off by the scraper 16. As described above, the lower part of the second filtration space 11, that is, the vicinity of the supply ports 10A, 10A,..., Is mainly subjected to filtration and concentration by solid-liquid separation, so at least the supply ports 10A, 10A, ... Scraper should be installed near the side.

  The partition 3 may have a uniform spiral pitch throughout the second filtration space 11, but in order to eliminate unevenness (distribution) in the moisture content of the discharged cake, as shown in FIGS. 1 and 5. In addition, it is preferable that the spiral partition 3 is configured such that the pitch interval becomes shorter as it goes from the bottom plate 7B side of the casing 7 to the upper plate 7A side. In the upper part, it is preferable to shorten the spiral pitch and narrow the discharge path of the cake to enhance the pressing effect. On the other hand, although not shown, when the radius difference between the inner and outer filter media 1 and 2 is narrowed in the upper part of the second filtration space 11 to improve dewatering efficiency (for example, a conical shape or a multistage cylindrical shape), a spiral is used. You may comprise so that the pitch space | interval may become long as the shape partition 3 goes to the upper plate 7A side from the bottom plate 7B side of the casing 7.

  Although not shown, a hole through which the cake can pass can be formed in a part of the spiral blade to promote stirring and mixing of the cake. Furthermore, the lower part of the spiral blade may be cut in the lower part of the second filtration space 11.

  As shown in FIGS. 1 and 5, the scraper 16 extends at least one of the upper plate 7 </ b> A and the bottom plate 7 </ b> B of the casing 7 along the inner and outer peripheral edges of the partition 3 in the axial direction of the casing 7. It is conceivable to install it as an end. Moreover, although not shown in figure, you may install so that the periphery of the partition 3 adjacent to an axial direction may be bridged and connected. In FIG. 5, one scraper 16 is attached to each of the inner peripheral edge and the outer peripheral edge, but the scraper 16 may be attached to a plurality of locations. As a modification, the scraper 16 may be attached only to the lower part of the second filtration space 11 where solid-liquid separation is the main. In addition, the scraper 16 is not attached in parallel to the axial direction but is not shown, but the scraper 16 may be attached to the respective leading ends along the inner and outer peripheral edges of the partition 3.

  As described above, the scraper itself may be made of rubber, resin, or the like that can be pressed against the filtration surface by elastic force. However, as a modification, a spring is attached to the tip of the scraper. A blade having a function of making the blade movable in the radial direction of the inner filter medium 1 and the outer filter medium 2 by using a spring or the like can be used.

  Here, the relationship with the inner side filter medium 1, the outer side filter medium 2, and the partition 3 is demonstrated. The liquid to be processed fed from the liquid feed pipe 10 via the supply port 10A has a low cake concentration and fluidity, and the bottom plate of the inner filter medium 1 forming the first filtration space 4 Filtration concentration occurs through the filter medium of the inner filter medium 1 and the outer filter medium 2 in the lower part of 1B and the second filtration space 11. In the lower part of the first filtration space 4 and the second filtration space 11, filtration concentration by solid-liquid separation action is an important function, but when the filtration concentration progresses to some extent, the concentrated cake adheres to the filtration surface, Filtration efficiency decreases. Therefore, in order to maintain the concentration efficiency, in the second filtration space 11, the scraper 16 is attached to the partition 3, and the surfaces of the filter medium in the inner filter medium 1 and the outer filter medium 2 are scraped at a high frequency, thereby being fixed to the surface. Scraping the cake. Further, in the first filtration space 4, as described above, the liquid feed pipe 10 to be treated and the inner filter medium 1 are structurally separated so that they do not rotate together. By attaching a scraper (not shown) to the upper edge of 6,..., The cake captured on the filtration surface can be scraped with this scraper.

  Moreover, since the cake which lost fluidity | liquidity by the concentration effect | action produces a frictional force with a filter medium, it is conveyed by the rotating filter medium in the circumferential direction of the inner and outer filter media 1,2. However, a spiral (ribbon screw-shaped) partition 3 is arranged in the second filtration space 11, and the cake rotating along the inner and outer filter media 1, 2 interferes with this partition 3, It rotates about the axis and moves in the axial direction. The cake is finally discharged from the cake outlet 14 formed in the upper part of the second filtration space 11 while being filtered and concentrated by this movement. As will be described later, a back pressure plate 15 for suppressing cake discharge is attached to the cake discharge port 14, and the cake is consolidated in the second filtration space 11 by forcibly suppressing the discharge amount. In addition, the water content can be further reduced.

  Although the 2nd filtration space 11 concerning an embodiment has shown the annular thing which has the same cross section from the top to the bottom, the lower part of the 2nd filtration space 11 is large in order to secure a processing amount. In order to improve the dewatering efficiency in the upper part of the second filtration space 11, the radius difference between the inner and outer filter media 1 and 2 may be narrowed (for example, a conical shape or a multi-stage). Cylindrical shape).

  As shown in FIGS. 1 and 2, the inner cleaning pipe 8 is provided along the inner peripheral surface of the inner filter medium 1, and a plurality of cleaning nozzles 8 </ b> A, 8 </ b> A,. The inner cleaning tube 8 is attached so as to face the peripheral surface. Similarly, the outer cleaning pipe 9 is provided along the outer peripheral surface of the outer filter medium 2, and the outer cleaning pipe 9A, 9A,... It is attached to the tube 9. Then, while rotating the inner filter medium 1 and the outer filter medium 2 around the axis, the cleaning water is jetted from the plurality of cleaning nozzles 8A, 8A,..., 9A, 9A,. 2 filtration surface is washed. The washing water sprayed at the time of washing is finally discharged from the filtrate outlets 12 and 13 together with the filtrate as washing waste water.

  Here, the inner and outer filter media 1 and 2 are sprayed and washed with a high-pressure and high-temperature washing liquid, but it is preferable to wash by washing with an alkaline chemical as the washing liquid. In addition, it is more preferable to install an ultrasonic transmitter on the filtration surfaces of the inner and outer filter media 1 and 2 to vibrate and clean the filter media themselves, since the cleaning power is improved.

  In addition, you may make it wash | clean the bottom plate 1B by attaching the washing nozzle 8A of the inner side washing | cleaning pipe | tube 8 so that the bottom plate 1B of the inner side filter medium 1 may be opposed. Further, the installation positions of the inner and outer cleaning pipes 8 and 9 and the cleaning nozzles 8A and 9A are not limited to the above, but are installed in the second filtration space 11, and a cleaning nozzle (not shown) is attached to the partition 3 or the like. The cleaning liquid may be ejected from the second filtration space 11. Further, a plurality of inner and outer cleaning tubes 8 and 9 may be installed.

  As shown in FIG. 4, the cake discharge port 14 is formed in the part which projected the 2nd filtration space 11 in the upper board 7A of the casing 7, From this, the dehydrated cake is discharged | emitted. A back pressure plate 15 is attached to the cake discharge port 14. The back pressure plate 15 generates discharge resistance, and by adjusting the amount of sludge to be discharged, the cake is further squeezed and the moisture content is reduced. Thus, the volume can be reduced.

<The filtration method according to the present invention>
The filtration method using the filtration apparatus according to the present invention will be described below.
First, the liquid to be treated is fed into the first filtration space 4 through the supply ports 10A, 10A,... The liquid to be treated fed into the first filtration space 4 is stirred and mixed by the bottom plate 1B of the inner filter medium 1 while being stirred by the blades 6, 6,... Rotating as the inner filter medium 1 rotates. Moreover, it is pumped in the direction of the outer side filter medium 2 which forms an outer peripheral part. Then, the liquid to be treated is two-side filtered by the inner filter medium 1 and the outer filter medium 2 while rising spirally along the partition 3 in the second filtration space 11. The inner filter medium 1 and the outer filter medium 2 are respectively rotated by first and second rotation driving means (not shown) such as a motor. At this time, if necessary, the inner filter medium 1 and the outer filter medium 2 are rotated in the same direction with a speed difference. The inner filter medium 1 and the outer filter medium 2 do not necessarily need to be rotated, and only one of them may be rotated.

  The liquid to be treated rises along the partition 3 due to the pumping pressure and the rotational frictional force, but solid-liquid separation is performed in the lower part of the second filtration space 11 between the inner filter medium 1 and the outer filter medium 2. The upper portion of the cake is dewatered by pressing and finally a cake discharge port 14 is formed, from which the dehydrated cake is discharged.

  By rotating the inner filter medium 1 and the outer filter medium 2 and preventing the partition 3 from rotating, the scraper 16 scrapes off the cake accumulated on the respective filtration surfaces. At this time, as described above, the cleaning surfaces of the clogged inner filter medium 1 and outer filter medium 2 are cleaned by spraying cleaning water from the plurality of cleaning nozzles 8A, 8A,..., 9A, 9A,. The sprayed wash water is stored as wash wastewater on the bottom plate 7B of the casing 7 in the inner filter medium 1 and the bottom plate 7B between the casing 7 and the outer filter medium 2 together with the filtrate. It is discharged from the outlets 12 and 13.

  A cake having a high water content after solid-liquid separation rises in the upper part of the second filtration space 11, and this cake is caused by rotational friction between the inner filter medium 1 and the outer filter medium 2, and a back pressure plate. The squeezing is promoted by the discharge resistance of 15, the water content is reduced, and the volume is reduced and discharged from the cake discharge port 14.

It is a longitudinal cross-sectional view of the filtration apparatus which concerns on this invention. It is the II sectional drawing (transverse sectional view). It is the II-II sectional view (transverse sectional view). FIG. It is the schematic for demonstrating the relationship between a partition and a scraper.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Inner filter medium, 1A ... Upper plate, 1B ... Bottom plate, 2 ... Outer filter medium, 3 ... Partition, 4 ... Storage space (1st filtration space), 5 ... Inner cylinder rotating shaft, 6 ... Blade plate (impeller), DESCRIPTION OF SYMBOLS 7 ... Casing, 7A ... Top plate, 7B ... Bottom plate, 8 ... Inner washing pipe, 9 ... Outer washing pipe, 10 ... Liquid to be processed feeding, 10A ... Supply port, 11 ... Second filtration space, 12 ... Filtration Liquid outlet, 13 ... filtrate outlet, 14 ... cake outlet, 15 ... back pressure plate, 16 ... scraper.

Claims (10)

A cylindrical or conical inner and outer filter media, concentrically disposed within the casing;
A spiral partition provided between the outer peripheral surface of the inner filter medium and the inner peripheral surface of the outer filter medium,
A filtration device configured to feed a liquid to be treated from one end of the casing, discharge a cake from the other end of the casing, and discharge the filtrate that has passed through the inner filter medium and the outer filter medium to the outside. And
A storage space for storing the liquid to be treated is formed between one end side of the casing and the end plate of the inner filter medium,
A filtration space is formed between the outer peripheral surface of the inner filter medium and the inner peripheral surface of the outer filter medium so as to communicate with the storage space,
The inner filter medium and / or the outer filter medium rotate around an axis, and the spiral partition is configured not to rotate.
A filtration device characterized by that.   In the storage space, a blade plate rotating around the coaxial center with the inner filter medium and the outer filter medium is provided, and the liquid to be processed is stirred by the blade plate and the liquid to be processed is pumped in the radial direction. The filtration device according to claim 1. The end plate of the inner filter medium is formed of a filter medium so that the storage space is the first filtration space,
The filtration device according to claim 1 or 2, wherein a filtration space between an outer peripheral surface of the inner filter medium and an inner peripheral surface of the outer filter medium is configured as a second filtration space.   The filtration device according to claim 3, wherein the blade plate is configured to be close to or in contact with the filtration surface of the end plate of the inner filter medium, and the blade plate and the inner filter medium are rotated with a speed difference.   The filtration device according to any one of claims 1 to 4, wherein at least an inner peripheral edge and an outer peripheral edge of the spiral partition on the inlet side of the liquid to be processed are close to or in contact with the inner filter medium and the outer filter medium, respectively. .   The filtration device according to any one of claims 1 to 5, wherein a rotation speed of the inner filter medium and a rotation speed of the outer filter medium are rotatable with a speed difference.   The inner filter medium is provided with a first rotation drive means, the outer filter medium is provided with a second rotation drive means, and the first rotation drive means and the second rotation drive means are separate from the rotation drive means. The filtration device according to any one of claims 1 to 6, wherein   The filtration device according to any one of claims 1 to 7, wherein the spiral partition is configured such that a pitch interval is shortened from the one end side to the other end side.   The axial center is vertically oriented, the entire apparatus is vertically oriented, and the liquid to be treated is configured to be fed in a pressurized state from below to above. The filtration device described.   The filtration device according to any one of claims 1 to 8, wherein the shaft center is horizontally oriented and the entire device is horizontally oriented.

Images